The given expression is 2x-3 .
So when x =1, we will get 2(1)-3 = 2-3 =-1
When x=2, we will get, 2(2) -3 = 4-3 =1
When x=3, we will get 2(3)-3 = 6-3=3
When x=4, we will get 2(4)-3 = 8-3=5
So the required result of the expansion is -1+1+3+5=8
Correct option is the second option .
Answer:
The answer is "
"
Step-by-step explanation:
Given:
2x - 6y = 14
2x = 6y + 14
x = 3y + 7.....so sub in 3y + 7 for x in the other equation
4x - y = 9
4(3y + 7) - y = 9
12y + 28 - y = 9
12y - y = 9 - 28
11y = - 19
y = -19/11
x = 3y + 7
x = 3(-19/11) + 7
x = -57/11 + 7
x = -57/11 + 77/11
x = 20/11
solution is : (20/11, -19/11) <==
We have been given that the speed of elephants is 5km/h east and his speed is 41km/h west.
We have to find after how long will he be 13km from the herd.
Since the biologist is going to the west and the elephants towards east, their relative speed will be calculated by adding their respective speeds.
So final their relative speed will be:
= 5 km/h + 41 km/h
= 46 km/h
Now we want their distance to be 13 km and we have calculated relative speed as 46 km/h.
So using formula :
Speed = Distance / Time,
We calculate time as :
= Distance / Speed
= 13 / 46
= 0.28 hours
= 16.8 minutes.
So after 16.8 minutes, biologist will be 13 km away from the herd.
